Unknown battery and possible charging recommendations

 

I was given 4 batteries.  They are velcroed together (two each) to form what
I suspect to be a 12 volt configuration so that the two cells together are
about the size of a small car battery.  I believe them to be 6 volt lead
acid batteries only because they have a Pb recycle label on them.  The only
other marking I can find on them is the number "971226B", but a google
doesn't help with that number. They are black cased, 6.5"x7"x3" with sturdy
lead terminals.

I've had them sitting in my garage for about 2 years and forgot about them
until just recently when I decided to start doing some solar/wind projects.
I measured the output at about 5 volts so that is why I came to the
conclusion that they were 6 volt units.  They seem to hold a charge at about
7 volts from a trickle.  I didn't want to, but I accidently left one
charging over night at that level...

I have 2 solar cells rated at 5 watts each - putting out about 13.5vdc at
.450 amps max.

I also have 2 old (but mint condition - because I never used them) TC25G
generators.  I made a small turbine for one, but haven't done the gear box
yet.

My questions are:

1.  Got any clue of where I can find specs on these batteries?

2.  Do you think they would be good for a small solar/wind system?

3.  In a 12 volt solar configuration (2 batteries in series - to form one 12
volt battery - giving me a total of two 12 volt batteries), what would be
the recommended solar configuration?:

    a.  should I put both 12 volt batteries in parallel with both solar
cells in parallel (with a diode on each solar cell, of course)?

    b.  should I charge each 12 volt battery separately from one solar cell
each?

4.  Do I need a charge controller on such a small system?

5.  Do you have a link to any good sites with DIY charge controllers (I can
read schematics and do electronics fairly well)?

 



     It probaby is an academic question.  If those batteries were left sitting
you years, they are probably sulfated.  You may measure voltage, but they will
store very little energy.


     Even if they were good, they are probably a bit small, but it depends on
your application.

     Two 12 volt batteries in parallel.  The configuration of the solar cells
depends on their open-circuit voltage, but probably in parallel.

     That would require two charge controllers.

     In this case, size does not matter.  Yes, you need a charge controller
unless you want to fry your batteries.

     Google is your friend.

     Just a quick story; I purchased my PV panels from the estate of a friend.
Looking at his installation, it was obvious that they had not been used in some
time.  Closer inspection revealed a series of batteries, including a large
marine deep cycle unit, all bone-dry from gross overcharging.  For some strange
reason, he apparently never figured out that he needed a charge controller.

Vaughn

 



sitting

You are bumming me out...  Looks like 2 of the 4 are still good.  Makes me
think there is some interesting physics going on here...  Possibly switching
the batteries from left to right output - in other words... use them in
series, but swap the duty poles of the 6 volt batteries.


Run some fans for now - through an inverter - .5a @ 115ac per fan.  It is
just a test at the moment.  I can get more of these batteries without cost.


controller

Google tells me I don't need a charge controller for this amperage.
However, I did find a schematic for a charge controller rated up to 1a @
12vdc.  Probably cost me about 5 bucks to make.


friend.

strange

controller.

That sucks...  I've been checking out golf cart batteries as they seem to
fit my needs/cost more than any others.

My eventual goal is to get off the grid.  I know it will cost me more in the
long run - but I just don't like to pay monthly bills.  The grid is an
incredibly annoying situation and way out of my control - but batteries are
a serious drawback...

 



    Yes, I know that some people make the case that this is true, but my
experience is different.

    In the 80's, I ruined a series of auto-sized batteries in some generators
that I was responsible for with tiny 1 amp (supposedly regulated) trickle
chargers.  It took me longer that it should of to figure it out, but my
batteries were lasting about 6 months.  Now I always use real float chargers (or
charge controllers for PV) I have not had a premature battery failure in years.

Vaughn

 

Piccolo Pete wrote:

Oh,that sounds interesting,care to share the circuit/URL?  :-)